Respiratory care devices are commonly used as a means to deliver gases and medication in an aerosolized form to a patient. Aerosolized medication is typically used to treat patients with respiratory conditions, such as reactive airways disease, asthma, bronchitis, emphysema, or chronic obstructive pulmonary disease (COPD), bronchiectasis, cystic fibrosis, etc.
It is generally accepted that effective administration of aerosolized medication depends on the delivery system and its position in relation to the patient. Aerosol particle deposition is influenced by particle size, ventilatory pattern, and airway architecture, and effective medication response is influenced by the dose of the medication used.
An aerosol delivery system includes three principal elements, namely a generator, a power source, and an interface. Generators include small volume nebulizers (SVN), large volume nebulizers (LVN), metered dose inhalers (MDI), and dry powder inhalers (DPI). The power source is the mechanism by which the generator operates or is actuated and includes compressed gas for SVN and LVN and self-contained propellants for MDI. The interface is the conduit between the generator and the patient and includes spacer devices/accessory devices with mouthpieces or face masks. Depending on the patient's age (ability) and coordination, various interfaces are used in conjunction with SVN and MDI in order to optimize drug delivery.
The three primary means for delivering aerosolized medication to treat a medical condition is an MDI, a DPI, or a nebulizer. MDI medication (drug) canisters are typically sold by manufacturers with a boot that includes a nozzle, an actuator, and a mouthpiece. Patients can self-administer the MDI medication using the boot alone but the majority of patients have difficulty synchronizing the actuation of the MDI canister with inhalation causing oropharyngeal drug deposition, decreased drug delivery and therefore effectiveness, and causes other adverse effects.
A dry powder inhaler (DPI) is a device that delivers medication to the lungs in the form of a dry powder. DPIs are an alternative to the aerosol based inhalers commonly called metered-dose inhaler (or MDI). The DPIs may require some procedure to allow a measured dose of powder to be ready for the patient to take. The medication is commonly held either in a capsule for manual loading or a proprietary form from inside the inhaler. Once loaded or actuated, the operator puts the mouthpiece of the inhaler into their mouth and takes a deep inhalation, holding their breath for 5-10 seconds. There are a variety of such devices. The dose that can be delivered is typically less than a few tens of milligrams in a single breath since larger powder doses may lead to provocation of cough. Most DPIs rely on the force of patient inhalation to entrain powder from the device and subsequently break-up the powder into particles that are small enough to reach the lungs. For this reason, insufficient patient inhalation flow rates may lead to reduced dose delivery and incomplete deaggregation of the powder, leading to unsatisfactory device performance. Thus, most DPIs have a minimum inspiratory effort that is needed for proper use and it is for this reason that such DPIs are normally used only in older children and adults.
Small volume nebulizers (SVN) and large volume nebulizers (LVN) have been used to overcome difficulties encountered with MDI and DPI during acute exacerbation of obstructive airways disease but even these devices are fraught with problems especially significant waste of medication and not adequately reaching the target airways.
Problems with prior art devices include that the devices are inefficient and significantly waste medication, they provide a non-uniform concentration of delivered medication, they are expensive, and they are difficult to use. In addition, multiple pieces of equipment are needed to treat a plurality of different conditions.
The modular pulmonary treatment system of the present invention overcomes these deficiencies and provides a system that includes a number of interchangeable parts that allow the system to have a number of different operating modes including but not limited to delivery of a gas to a patient; delivery of an aerosolized medication (drug) to a patient; and a combination thereof.